Continuous apparatus for chemical conversion of materials

Abstract

A process and apparatus for the acid hydrolysis of waste cellulose to glucose of the type wherein waste cellulose is continuously fed into an inlet port of a twin screw extruder, water is continuously fed into reaction zone in the extruder, downstream of the inlet port, the cellulose is continuously reacted with water in the presence of an acid catalyst at elevated temperature and pressure in the reaction zone while being continuously conveyed to an outlet port of the extruder having a given diameter and the reacted cellulose is discharged from the extruder while the elevated temperature and pressure in the reaction zone is maintained. The elevated pressure is maintained by forming a dynamic seal zone at the upstream end of the reaction and continuously discharging the reacted material downstream of the outlet port at a predetermined volume rate of flow to maintain the pressure by passing the discharge through an orifice pipe having a smaller diameter than the given diameter of the outlet port.

What is claimed is: 
     
       1. In an apparatus for the acid hydrolysis of waste cellulose to glucose of the type having extruding means comprising a housing having means defining a cellulose inlet port receptive of waste cellulose, means defining a steam inlet port and means associated therewith for introducing steam into the cellulose, means defining an outlet port, and a reaction zone between the cellulose inlet port and the outlet port, and twin screws for continuously conveying the waste cellulose through the reaction zone towards the outlet port, means for continuously feeding the waste cellulose to the cellulose inlet port and means for maintaining an elevated temperature and pressure within the reaction zone during discharge, the improvement wherein the maintaining means maintains an elevated pressure of 135 psi to 1000 psi and solely comprises means forming a dynamic seal in the twin screws at the upstream end of the reaction zone and a continuously open discharge orifice pipe downstream of the outlet port configured to permit a predetermined volume of flow necessary to maintain the elevated pressure. 
     
     
       2. The apparatus according to claim 1, wherein the orifice pipe is configured according to ##EQU2## where Q is the volume rate of flow, P O  -P L  is the pressure differential across the orifice pipe, R is the radius of the pipe, L is the length of the pipe and μ is the viscosity of the reacted cellulose and wherein the radius of the pipe is smaller than that of the outlet port. 
     
     
       3. The apparatus according to claim 2, further comprising means disposed upstream of the orifice pipe for screening the discharge fed thereto to remove particles and prevent clogging. 
     
     
       4. The apparatus according to claim 3, further comprising means for continuously injecting sulfuric acid into the reaction zone. 
     
     
       5. The apparatus according to claim 4, further comprising means for continuously injecting steam into the reaction zone. 
     
     
       6. The apparatus according to claim 5, further comprising means for pretreating the cellulose material before being received by the feeding means including means for irradiating the cellulose material. 
     
     
       7. The apparatus according to claim 6, wherein the means for continuously feeding the cellulose waste material comprises means for continuously feeding dry cellulose material into the inlet port. 
     
     
       8. The apparatus according to claim 7, wherein the means for continuously feeding water comprises at least one of means for continuously feeding water with the acid catalyst and means for continuously feeding water just upstream of the dynamic seal. 
     
     
       9. In an apparatus for the chemical conversion of solid materials in a multiphase reaction mixture, the apparatus being of the type having extruding means comprising a housing having means defining a solids inlet port receptive of the material to be converted, means defining a gas inlet port and means associated therewith to supply a gas phase reactant to the solid materials, means defining an outlet port and a reaction zone between the solids inlet port and the outlet port and twin screws for continuously conveying the material through the reaction zone and to the outlet port, means for continuously feeding the material to the inlet port; means for maintaining an elevated pressure within the reaction zone during discharge, the improvement wherein the maintaining means solely comprises means forming a dynamic seal at the upstream end of the reaction zone and a continuously open discharge orifice pipe downstream of the outlet port configured to permit a predetermined volume of flow necessary to maintain the elevated pressure. 
     
     
       10. The apparatus according to claim 9, wherein the orifice pipe is configured according to ##EQU3## where Q is the volume rate of flow, P O  -P 2  is the pressure differential across the orifice pipe and R is the radius of the pipe, L is the length of the pipe and μ is the viscosity of the reacted cellulose and wherein the radius of the pipe is smaller than that of the outlet port. 
     
     
       11. The apparatus according to claim 10, further comprising means disposed upstream of the orifice pipe for screening the discharge fed thereto to remove particles and prevent clogging.